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From: Tomas Winkler <tomas.winkler@intel.com>
To: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexander Usyskin <alexander.usyskin@intel.com>,
	Vitaly Lubart <vitaly.lubart@intel.com>,
	linux-kernel@vger.kernel.org,
	Tomas Winkler <tomas.winkler@intel.com>
Subject: [char-misc-next] mei: bus-fixup: set timeout for MKHI send operations
Date: Sat, 15 Jun 2024 09:31:59 +0300
Message-ID: <20240615063159.1460290-1-tomas.winkler@intel.com>
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From: Alexander Usyskin <alexander.usyskin@intel.com>

Set a timeout for MKHI client send operations in the bus fixup routines
to prevent potential lock-ups on the cl_bus_lock mutex.
In rare conditions, such as when the i915 or Xe driver is stopping and
not routing interrupts or when GSC FW is in unexpectedly reset the fixup
routines can get stuck.

Signed-off-by: Alexander Usyskin <alexander.usyskin@intel.com>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
---
 drivers/misc/mei/bus-fixup.c | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/drivers/misc/mei/bus-fixup.c b/drivers/misc/mei/bus-fixup.c
index 2733070acf39eabfd606da38..9eebeffcd8fd0645cecba167 100644
--- a/drivers/misc/mei/bus-fixup.c
+++ b/drivers/misc/mei/bus-fixup.c
@@ -80,6 +80,8 @@ static void whitelist(struct mei_cl_device *cldev)
 	cldev->do_match = 1;
 }
 
+#define MKHI_SEND_MAX_TIMEOUT_MSEC 4000
+
 #define OSTYPE_LINUX    2
 struct mei_os_ver {
 	__le16 build;
@@ -128,7 +130,7 @@ static int mei_osver(struct mei_cl_device *cldev)
 	os_ver = (struct mei_os_ver *)fwcaps->data;
 	os_ver->os_type = OSTYPE_LINUX;
 
-	return __mei_cl_send(cldev->cl, buf, size, 0, mode);
+	return __mei_cl_send_timeout(cldev->cl, buf, size, 0, mode, MKHI_SEND_MAX_TIMEOUT_MSEC);
 }
 
 #define MKHI_FWVER_BUF_LEN (sizeof(struct mkhi_msg_hdr) + \
@@ -148,8 +150,8 @@ static int mei_fwver(struct mei_cl_device *cldev)
 	req.hdr.group_id = MKHI_GEN_GROUP_ID;
 	req.hdr.command = MKHI_GEN_GET_FW_VERSION_CMD;
 
-	ret = __mei_cl_send(cldev->cl, (u8 *)&req, sizeof(req), 0,
-			    MEI_CL_IO_TX_BLOCKING);
+	ret = __mei_cl_send_timeout(cldev->cl, (u8 *)&req, sizeof(req), 0,
+				    MEI_CL_IO_TX_BLOCKING, MKHI_SEND_MAX_TIMEOUT_MSEC);
 	if (ret < 0) {
 		dev_info(&cldev->dev, "Could not send ReqFWVersion cmd ret = %d\n", ret);
 		return ret;
-- 
2.45.0